Transmission Blasting, Aluminium Oxide 100 grit OK Options

[rstover]

I recently had the fan housing cerakoted and now I want to do the transmission. On the fan housing I removed all the grease and oil and the shop that applied the cerakote blasted it withe 200 grit aluminium oxide in a cabinet and it came out great.

I will get all the grease and oil off the transmission, but the blasting will be done with 100 grit aluminum oxide outside of a cabinet. I believe I have protected everything but was a little concerned about 100 grit being to course.

[toolguy]

I wouldn't use sand. . I doubt that any tape or sealing will keep all
of the abrasive out. . I'd go with plastic beads if you can't do the soda or dry ice, which
would be my first choice for an assembled tranny. .
However, all of this is a substitute for doing it right. . pull the trans apart, blast it, then put in in a vibrator ceramic tumbler, and you'd have a perfect original finish . . .

This is bare Mag, no paint. . it was then coated with an Aerosapce metal protectant from Boeing called Boshield,T-9. It is similar to WD40, but dries to a waxy protectant finish that penetrates the pores of the mag. . I did mine 8 years ago and it looks the same today.

[Dr Evil]

I wouldn't use sand. . I doubt that any tape or sealing will keep all
of the abrasive out. . I'd go with plastic beads if you can't do the soda or dry ice, which
would be my first choice for an assembled tranny. .
However, all of this is a substitute for doing it right. . pull the trans apart, blast it, then put in in a vibrator ceramic tumbler, and you'd have a perfect original finish . . .

This is bare Mag, no paint. . it was then coated with an Aerosapce metal protectant from Boeing called Boshield,T-9. It is similar to WD40, but dries to a waxy protectant finish that penetrates the pores of the mag. . I did mine 8 years ago and it looks the same today.

This is the best response, but others hit the nail on the head with recommending not blasting it.

I have never had one blasted the didnt have some intrusion into the box. You are forcing small hard particles at the box very fast. They will find a way. And you only need one particle to get in to wreck a bearing, and then, and then....

Its not much effort to pull the thing apart, clean, blast, change all the gaskets, put back together. Just match the gasket between the intermediate plate and case.

When I had a friend with a washer, that was the best first step if you cant do all the exotic treatments mentioned here. The ones lke a giant dishwasher with jets and hot water based soap solution was great. Likely you can find a shop near by with one that will let you wash your stuff for cheap or free. Takes like 20min and comes out clean, but somewhat stained metal. Then, I have used Hammerite from Krylon to paint for easy effect.